1. Field
The present application relates to a method for controlling a power transmission in a wireless power transmission apparatus for improving a wireless power efficiency, and a wireless power transmission apparatus thereof.
2. Description of the Related Art
Generally, a battery pack receives electric power from an external charging device and supplies power for operating a portable terminal including a mobile phone and a Personal Digital Assistant (PDA) in a charged state. The battery pack includes a battery cell for charging the electric energy and a circuit for charging and discharging the battery cell, i.e., supplying the electric energy to a portable terminal.
An electrical connection method of the battery pack and the charging device for charging the electric energy to the battery pack used in the portable terminal includes a terminal supplying method for receiving the commercial electricity, converting the commercial electricity into voltage and current corresponding to the battery pack, and supplying the electric energy to the battery pack via the terminal of the corresponding battery pack.
However, when the power is supplied by the terminal supplying method, there is a problem that an instantaneous discharge phenomenon occurs since both terminals of the battery pack and the charging device have different potential differences when the charging device and the battery pack contact with or are separated from each other.
Particularly, when foreign objects are stacked up on one or both of the terminals, a fire may break out due to the instantaneous discharge phenomenon.
There are also problems that the electric energy charged in the battery pack is naturally discharged to the outside via the terminal of the battery pack due to moisture, which causes a reduction in the lifespan and a deterioration in the performance of the battery pack.
Recently, controlling methods and charging systems of a non-contact type using a wireless power transmission method have been suggested to solve the above-mentioned and/or other problems.
There have been studies for increasing the wireless power transmission efficiency as well as stable power reception in the wireless power transmission system.